PROJECT SUMMARY Human-animal interaction (HAI) programs to reduce psychological distress in children are increasingly common in medical and educational settings. Despite the popularity of HAI programs, research on the effectiveness of these programs suffers from many methodological limitations, including the use of small, select samples, reliance on self-report measures, and lack of adequate control comparisons. Of particular value for developing low-cost, scalable programs to prevent psychological distress would be determining whether brief interactions with dogs could serve as a protective factor that reduces distress related to a subsequent stressor, without the animal being present during the stressor (Aim 1). In addition, we lack knowledge of the mechanisms through which HAI reduces stress response (Aim 2). Finally, we have limited information on the individual characteristics that predict positive response to HAI interventions (Aim 3). The proposed study will use a community-based sample of 220 children aged 9 to 12 to address the above gaps. Effects of interaction with a therapy dog will be compared to effects of interaction with a stuffed animal dog as the control condition. All children will receive both interactions/interventions. Children will be randomly assigned to one of two study design arms based on the timing of the interventions as the key distinguishing variable; analyses will be primarily based on a between-subjects design. Child interactions with the therapy dog will be videotaped for behavioral coding of both the child's and the dog's behaviors to identify specific child and dog behaviors that are most strongly related to children's attenuated stress response. Biological stress reactivity will be assessed via cortisol response to stress using the well-validated, standardized Trier Social Stress Test for Children (TSST-C). Salivary samples will be obtained at baseline and at several points before, during, and after the social stress task. Children will also participate in a series of behavioral tasks assessing prosocial behaviors, and will fill out subjective mood ratings before and after the interaction with the therapy dog and the interaction with the stuffed animal dog. Parents will provide information on family characteristics, stressful life events, pet history, and emotional and behavioral problems in children. Children will fill out self- report questionnaires assessing attitudes towards pets and personality.